Motion detector for electronic devices

ABSTRACT

A motion detector ( 10 ) includes a chamber ( 102 ), a resilient suspension arm ( 104 ), an air bearing slider ( 110 ), at least one piezoresistive sensor ( 106 ), and an infrared sensor module ( 112 ). The chamber has a front plate ( 1024 ) and a back plate ( 1026 ) located on the opposite side of the chamber, and each of the front plate and the back plate has a first through hole ( 1030 ) and a plurality of second through hole ( 1032 ) formed therein. The resilient suspension arm is arranged in the chamber, and has a free distal end ( 1042 ). The air bearing slider is moveable coupled to the free distal end of the resilient suspension arm. The at least one piezoresistive sensor is attached on the air bearing slider. The infrared sensor module is arranged on the front plate of the chamber, for sensing infrared light.

BACKGROUND

1. Field of the Invention

The present invention relates to motion detectors which are capable ofdetecting a movement and thus producing a corresponding electronicsignal to electronic devices.

2. Description of Related Art

Many electronic games, especially video games, usually have a gameconsole provided to manipulates the video display signal of a displaydevice (a television, monitor, etc.) to display a game. However, most ofthe video games cannot bring game players real physical interaction withthe game console such that the video games become insipid. For solvingthe above problem, a conventional motion detector is employed in thegame console to detect and simulate motion of the game players forenhancing the enjoyment of playing video games. However, theconventional motion detector cannot accurately detect the motion of thegame players.

What is needed, therefore, is a motion detector which can accuratelydetect the motion of the game players.

SUMMARY OF THE INVENTION

A motion detector according to a present embodiment, includes a chamber,a resilient suspension arm, an air bearing slider, at least onepiezoresistive sensor, and an infrared sensor module. The chamber has afront plate and a back plate located on the opposite side of thechamber, and each of the front plate and the back plate has a firstthrough hole and a plurality of second through holes defined therein.The second through holes surround the first through hole. The resilientsuspension arm is arranged in the chamber, and has a free distal end.The air bearing slider is moveably coupled to the free distal end of theresilient suspension arm. The at least one piezoresistive sensor isattached on the air bearing slider. The infrared sensor module isarranged on the front plate of the chamber, for sensing infrared light.

The present motion detector employs the at least one piezoresistivesensor, which is attached on the air bearing slider. Therefore, themotion detector may accurately sense motions of game players.

Other advantages and novel features of the present invention will becomemore apparent from the following detailed description of presentembodiment when taken in conjunction with the accompanying drawings, inwhich:

BRIEF DESCRIPTION OF THE DRAWINGS

Many aspects of the present motion detector can be better understoodwith reference to the following drawings. The components in the drawingsare not necessarily to scale, the emphasis instead being placed uponclearly illustrating the principles of the present motion detector.Moreover, in the drawings, like reference numerals designatecorresponding parts throughout the several views.

FIG. 1 is a schematic view of a motion detector according to a presentembodiment of the present invention.

FIG. 2 is a schematic, partial-enlarged view of the motion detector ofFIG. 1.

FIG. 3 is a schematic view of a piezoresistive sensor of FIG. 1.

FIG. 4 is a schematic, side view of an infrared sensor module of FIG. 1.

DETAILED DESCRIPTION OF THE EMBODIMENT

Reference will now be made to the drawings to describe a presentembodiment of the present backlight module in detail.

Referring to FIGS. 1 and 2, a motion detector 10 in accordance with apresent embodiment, includes a chamber 102, a resilient suspension arm104, an air bearing slider 110, at least one piezoresistive sensor 106and an infrared sensor module 112.

The chamber 102 includes a front plate 1024 and a back plate 1026located on the opposite side of the chamber 102. The front plate 1024and the back plate 1026, each respectively has a first through hole 1030and a plurality of second through holes 1032 defined therein. The firstthrough holes 1030 are defined at a center of each of the front plate1024 and the back plate 1026, respectively. The second through holes1032 are distributed uniformly around of the corresponding first throughholes 1030, respectively. The second through holes 1032 surround thefirst through holes 1030, respectively. The first through hole 1030 ofthe front plate 1024 is aligned with the first through hole 1030 of theback plate 1026 in a first direction. The second through holes 1032 ofthe front plate 1024 are aligned with the respective second throughholes 1032 of the back plate 1026 in the first direction. In thisexemplary embodiment, the front plate 1024 and the back plate 1026, eachhas eight second through holes 1032 arranged around the first throughhole 1030, respectively. The first through hole 1030 is larger than eachof the second through holes 1032. The first through hole 1030 has afirst diameter, and each of the second through hole 1032 has a seconddiameter. The first diameter may be 3 to 10 times greater than thesecond diameter. Preferably, the first diameter is 4 to 6 times greaterthan the second diameter.

The first through holes 1030 and the second through holes 1032 definedon the front plate 1024 and the second plate 1026 respectively, areconfigured for permitting air to enter into the chamber 102 therethroughto form a laminar flow, when the motion detector 10 moves. The firstthrough hole 1030 is configured for permitting more air to flow into thechamber 102, and the second through holes 1032 are configured for makingthe laminar flow distribute uniformly. The chamber 102 further includesa plurality of side plates 1028 connecting the front plate 1024 and theback plate 1026, thereby constructs an enclosed box.

The resilient suspension arm 104 is disposed in the chamber 102. Theresilient suspension arm 104 has a distal end fixed on one of the sideplates 1028, and a free distal end 1042 opposite thereto. The resilientsuspension arm 104 may be comprised of stainless steel. The free distalend 1042 is located at a center of the chamber 102.

The air bearing slider 110 is moveably coupled to the free distal end1042 of the resilient suspension arm 104. A joint 108 is employed tointerconnect the free distal end 1042 of the resilient suspension arm104 and the air bearing slider 110, thus the air bearing slider 110 ismoveable relative to the free distal end 1042 of the resilientsuspension arm 104. Preferably, the joint is a gimbal joint.

The air bearing slider 110 is arranged between the two first holes 1030of the front plate 1024 and the back plate 1026. The air bearing slider110 is configured for detecting the laminar flow between the front plate1024 and the back plate 1026. Preferably, the air bearing slider 110 hasan inclining surface 1102 facing towards the first hole 1030 of thefront plate 1024. The inclining surface 1102 improves the sensitivecapability of the motion detector 10. In operation, the incliningsurface 1102 is impacted by the laminar flow, thereby the air bearingslider 110 is shaken along a flowing direction of the laminar flow. Theair bearing slider 110 is comprised of a combination of aluminum oxide(Al₂O₃) and titanium carbide (TiC). A percentage by weight of aluminumoxide is in a range of 60% to 80%, and a percentage by weight oftitanium carbide is in a range of 20% to 40%.

The at least one piezoresistive sensor 106 is attached on the airbearing slider 110 for sensing pitch, roll and yaw as associated withthe motions of the motion detector 10. In this exemplary embodiment, themotion detector 10 includes two piezoresistive sensors 106, and one isattached on an upper surface of the air bearing slider 110 and anotheris attached to a side surface of the air bearing slider 110. The atleast one piezoresistive sensor 106 is configured for sensing thelaminar flow and is shaken with the air bearing slider 110 in theflowing direction of the laminar flow.

Referring to FIG. 3, the at least one piezoresistive sensor 106 includesa substrate 1062, a silicon layer 1064 formed on the substrate 1062, anda silicon dioxide layer 1066 formed on the silicon layer 1064. Thesubstrate 1062 is attached on the air bearing slider 110, and comprisedof a material same as that of the air bearing slider 110. That is, thesubstrate 1062 is comprised of the combination of aluminum oxide andtitanium carbide, and the percentage by weight of aluminum oxide is in arange of 60% to 80% and the percentage by weight of titanium carbide isin a range of 20% to 40%. The at least one piezoresistive sensor 106further includes a plurality of grooves 1068 formed thereon, and each ofthe plurality of grooves 1068 extends from the silicon dioxide layer1066 to the silicon layer 1064 in a thicknesswise direction. In thisexemplary embodiment, the grooves 1068 are spaced a uniform intervalfrom one another. Each of the grooves 1068 has a width W1. A distance W2is defined between each neighboring two grooves 1068. The distance W2can be 2 to 5 times larger than the width W1. Preferably, the distanceW2 is 3 to 4 times larger than the width W1. The grooves 1068 may beformed by a reactive ion etching process. The silicon layer 1064 has awidth in a range of 100 to 1000 nanometers, preferably, in a range of200 to 500 nanometers. The silicon dioxide layer 1066 has a width in arange of 50 to 200 nanometers, preferably, in a range of 80 to 120nanometers. The silicon dioxide layer 1066 may be manufactured by a CVDprocess.

The infrared sensor module 112 is attached on the front plate 1024 ofthe chamber 102. Referring to FIG. 4, the infrared sensor module 112includes a sensor 1122, an infrared passband filter 1124, an asphericallens 1126 and an infrared glass 1128 arranged coaxially. The sensor 1122may be a Complementary Metal Oxide Semiconductor (CMOS) or a ChargeCouple Device (CCD). The infrared glass 1128 is configured for filteringthe visible light and permitting the infrared light to passtherethrough. The infrared sensor module 112 is configured for receivingthe infrared light to sense the motions of the motion device 10 andproduce corresponding signals.

The infrared passband filter 1124 has a high transmission capability.The transmission capability of the infrared passband filter 1124 is morethan 90% for light in a range of 900˜1000 nanometers and thetransmission capability thereof is less than 2% for light in a range of600˜800 nanometers or light in a range of 1100˜1200 nanometers. Theinfrared passband filter 1124 has multi-layers comprised of titaniumdioxide and silicon dioxide.

In operation, when the motion detector 10 moves, the air flows into thechamber 102 to form the laminar flow and impact the air bearing slider110, so that the at least one piezoresistive sensor 106 may accuratelysense the motions of the game players to produce corresponding signals.

Furthermore, the motion detector 10 may further includes a digitalsignal processing board, a mother board, a blue tooth board, a RF inputand output board, a power management board, a power, etc. The signalsproduced by the at least one piezoresistive sensor 106 and the infraredsensor module 112 may be transmitted to the digital signal processingboard or the motherboard for processing. The processed signals are thentransmitted out through the blue tooth board or the RF input and outputboard.

It is to be understood, however, that even though numerouscharacteristics and advantages of the present invention have been setforth in the foregoing description, together with details of thestructure and function of the invention, the disclosure is illustrativeonly, and changes may be made in detail, especially in matters of shape,size, and arrangement of parts within the principles of the invention tothe full extent indicated by the broad general meaning of the terms inwhich the appended claims are expressed.

1. A motion detector, comprising: a chamber having a front plate and a back plate located on two opposite sides of the chamber, each of the front plate and the back plate having a first through hole and a plurality of second through holes defined therein, the second through holes surrounding the first through hole; a resilient suspension arm arranged in the chamber, the resilient suspension arm having a free distal end; an air bearing slider moveably coupled to the free distal end of the resilient suspension arm; at least one piezoresistive sensor attached on the air bearing slider for sensing pitch, roll and yaw associated with the motions of the motion detector; and an infrared sensor module arranged on the front plate of the chamber, for sensing infrared light.
 2. The motion detector as claimed in claim 1, further comprising a gimbal joint interconnecting the free distal end of the resilient suspension arm and the air bearing slider, thus the air bearing slider being moveable relative to the free distal end of the resilient suspension arm.
 3. The motion detector as claimed in claim 2, wherein the resilient suspension arm is comprised of stainless steel.
 4. The motion detector as claimed in claim 1, wherein the first through hole is arranged at the center of each of the front plate and the back plate.
 5. The motion detector as claimed in claim 4, wherein the first through hole is larger than each of the second through holes.
 6. The motion detector as claimed in claim 5, wherein the first through hole has a first diameter, each of the second through holes has a second diameter, and the diameter of the first diameter is 3 to 10 times greater than that of the second diameter.
 7. The motion detector as claimed in claim 1, wherein the air bearing slider is comprised of a combination of aluminum oxide and titanium carbide, and a percentage by weight of aluminum oxide is in a range of 60% to 80% and a percentage by weight of titanium carbide is in a range of 20% to 40%.
 8. The motion detector as claimed in claim 1, wherein the at least one piezoresistive sensor includes a substrate, a silicon layer formed on the substrate, and a silicon dioxide layer formed on the silicon layer.
 9. The motion detector as claimed in claim 8, wherein the substrate of the piezoresistive sensor is attached on the air bearing slider.
 10. The motion detector as claimed in claim 9, wherein the substrate is comprised of a combination of aluminum oxide and titanium carbide, and a percentage by weight of aluminum oxide is in a range of 60% to 80% and a percentage by weight of titanium carbide is in a range of 20% to 40%.
 11. The motion detector as claimed in claim 8, wherein the at least one piezoresistive sensor further includes a plurality of grooves formed thereon, and each of the grooves extends from the silicon dioxide layer to the silicon layer in a thicknesswise direction.
 12. The motion detector as claimed in claim 11, wherein the grooves are spaced a uniform interval from one another.
 13. The motion detector as claimed in claim 1, wherein the infrared sensor module includes a sensor, an infrared passband filter, an aspherical lens and an infrared glass arranged coaxially and optically. 